Chapter 4.3, 4.4, 4.5

Difference Threshold

The smallest physical change in a stimulus (like turning up the volume by one notch) that a person can notice 50% of the time.

Weber's Law

The rule that a change has to be a certain percentage of the original stimulus to be noticed (e.g., adding one candle to a dark room is noticeable, but adding one candle to a bright stadium is not).

Adaptation

When your brain stops paying attention to a constant, unchanging stimulus (like the feeling of your clothes on your skin).

Aftereffects

Weird visual or physical distortions you experience right after adapting to something (like staring at a moving waterfall, then looking at rocks and seeing them move upward).

Neurodiversity (in perception)

The idea that different people's brains naturally process sensory information in slightly different ways.

Natural Selection

The process where traits that help a species survive get passed down; in this context, it's why different animals evolved different dominant senses.

Visual Disabilities

Any condition where a person's eyesight cannot be corrected to a normal level with glasses or surgery.